<!doctype html>
<html lang="en">
<head>
	<meta charset="UTF-8" />
	<title>Document</title>
	<script src="js/jquery-1.11.2.js" type="text/javascript" charset="utf-8"></script>
</head>
<body>
	<div class='nav'>
		<p>你好！</p><span>world!</span>
	</div>
</body>
<script type="text/javascript">
/*	function getNum(){
		var num = parseInt(Math.random()*100);
		if(num%7 == 0){
			return num
		} else{
			return getNum()
		}
	}
alert (getNum())*/
	$(".nav span").html("世界!")
</script>
</html>